Apparatus, system and method of beamforming training

ABSTRACT

Some demonstrative embodiments include devices, systems and/or methods of wireless communication via multiple antenna assemblies. For example, a device may include a wireless communication unit to transmit and receive signals via one or more quasi-omnidirectional antenna assemblies, wherein the wireless communication unit is to transmit, via each quasi-omnidirectional antenna assembly, a plurality of first transmissions, to receive, in response to the first transmissions, a plurality of second transmissions from another device via one or more of the quasi-omnidirectional antenna assemblies, and, based on the second transmissions, to select at least one selected transmit antenna assembly for transmitting to the other device and a selected receive antenna assembly for receiving transmissions from the other device. Other embodiments are described and claimed.

CROSS-REFERENCE

This application is a Continuation Application of U.S. patentapplication Ser. No. 14/941,690, filed on Nov. 16, 2015, which is aContinuation Application of U.S. patent application Ser. No. 14/521,674,filed on Oct. 23, 2014, which is a Continuation Application of U.S.patent application Ser. No. 14/027,216, filed Sep. 15, 2013, which is aContinuation Application of U.S. patent application Ser. No. 12/639,044,filed Dec. 16, 2009 and entitled “Device, System and Method of WirelessCommunication Via Multiple Antenna Assemblies”, the entire disclosuresof which are incorporated herein by reference.

BACKGROUND

Beamforming may be used by antenna arrays for directional and/or spatialsignal transmission and/or reception.

A beamforming training session may be implemented by two wirelesscommunication devices in order, for example, to select effective receiveand/or transmit beamforming patterns to be used for wirelesscommunication between the devices.

BRIEF DESCRIPTION OF THE DRAWINGS

For simplicity and clarity of illustration, elements shown in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements may be exaggerated relative to otherelements for clarity of presentation. Furthermore, reference numeralsmay be repeated among the figures to indicate corresponding or analogouselements. The figures are listed below.

FIG. 1 is a schematic block diagram illustration of a system inaccordance with some demonstrative embodiments.

FIG. 2 is a schematic illustration of a training session, in accordancewith one demonstrative embodiment.

FIG. 3 is a schematic illustration of a training session, in accordancewith another demonstrative embodiment.

FIG. 4 is a schematic illustration of a training session, in accordancewith yet another demonstrative embodiment.

FIG. 5 is a schematic illustration of a training session, in accordancewith yet another demonstrative embodiment.

FIG. 6 is a schematic illustration of a method of communicating viamultiple antenna assemblies, in accordance with some demonstrativeembodiments.

FIG. 7 is a schematic illustration of an article of manufacture, inaccordance with some demonstrative embodiments.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of some embodiments.However, it will be understood by persons of ordinary skill in the artthat some embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components, unitsand/or circuits have not been described in detail so as not to obscurethe discussion.

Discussions herein utilizing terms such as, for example, “processing”,“computing”, “calculating”, “determining”, “establishing”, “analyzing”,“checking”, or the like, may refer to operation(s) and/or process(es) ofa computer, a computing platform, a computing system, or otherelectronic computing device, that manipulate and/or transform datarepresented as physical (e.g., electronic) quantities within thecomputer's registers and/or memories into other data similarlyrepresented as physical quantities within the computer's registersand/or memories or other information storage medium that may storeinstructions to perform operations and/or processes.

The terms “plurality” and “a plurality” as used herein include, forexample, “multiple” or “two or more”. For example, “a plurality ofitems” includes two or more items.

Some embodiments may be used in conjunction with various devices andsystems, for example, a Personal Computer (PC), a desktop computer, amobile computer, a laptop computer, a notebook computer, a tabletcomputer, a server computer, a handheld computer, a handheld device, aPersonal Digital Assistant (PDA) device, a handheld PDA device, anon-board device, an off-board device, a hybrid device, a vehiculardevice, a non-vehicular device, a mobile or portable device, a consumerdevice, a non-mobile or non-portable device, a wireless communicationstation, a wireless communication device, a wireless Access Point (AP),a wired or wireless router, a wired or wireless modem, a video device,an audio device, an audio-video (AN) device, a Set-Top-Box (STB), aBlu-ray disc (BD) player, a BD recorder, a Digital Video Disc (DVD)player, a High Definition (HD) DVD player, a DVD recorder, a HD DVDrecorder, a Personal Video Recorder (PVR), a broadcast HD receiver, avideo source, an audio source, a video sink, an audio sink, a stereotuner, a broadcast radio receiver, a flat panel display, a PersonalMedia Player (PMP), a digital video camera (DVC), a digital audioplayer, a speaker, an audio receiver, an audio amplifier, a gamingdevice, a data source, a data sink, a Digital Still camera (DSC), awired or wireless network, a wireless area network, a Wireless VideoArea Network (WVAN), a Local Area Network (LAN), a Wireless LAN (WLAN),a Personal Area Network (PAN), a Wireless PAN (WPAN), devices and/ornetworks operating in accordance with existing IEEE 802.11 (IEEE802.11-1999: Wireless LAN Medium Access Control (MAC) and Physical Layer(PHY) Specifications), 802.11a, 802.11b, 802.11g, 802. 11h, 802.11j,802.11n, 802.11 task group ad (TGad), 802.15.3c, 802.16, 802.16d,802.16e, 802.16f, standards and/or future versions and/or derivativesthereof, devices and/or networks operating in accordance with existingWireless-Gigabit-Alliance (WGA) and/or WirelessHD™ specifications and/orfuture versions and/or derivatives thereof, units and/or devices whichare part of the above networks, one way and/or two-way radiocommunication systems, cellular radio-telephone communication systems, acellular telephone, a wireless telephone, a Personal CommunicationSystems (PCS) device, a PDA device which incorporates a wirelesscommunication device, a mobile or portable Global Positioning System(GPS) device, a device which incorporates a GPS receiver or transceiveror chip, a device which incorporates an RFID element or chip, a MultipleInput Multiple Output (MIMO) transceiver or device, a Single InputMultiple Output (SIMO) transceiver or device, a Multiple Input SingleOutput (MISO) transceiver or device, a device having one or moreinternal antennas and/or external antennas, Digital Video Broadcast(DVB) devices or systems, multi-standard radio devices or systems, awired or wireless handheld device (e.g., BlackBerry, Palm Treo), aWireless Application Protocol (WAP) device, or the like.

Some embodiments may be used in conjunction with one or more types ofwireless communication signals and/or systems, for example, RadioFrequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM),Orthogonal FDM (OFDM), Time-Division Multiplexing (TDM), Time-DivisionMultiple Access (TDMA), Extended TDMA (E-TDMA), General Packet RadioService (GPRS), extended GPRS, Code-Division Multiple Access (CDMA),Wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrierCDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT),Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBee™,Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2G,2.5G, 3G, 3.5G, Enhanced Data rates for GSM Evolution (EDGE), or thelike. Other embodiments may be used in various other devices, systemsand/or networks.

The term “wireless device” as used herein includes, for example, adevice capable of wireless communication, a communication device capableof wireless communication, a communication station capable of wirelesscommunication, a portable or non-portable device capable of wirelesscommunication, or the like. In some demonstrative embodiments, awireless device may be or may include a peripheral that is integratedwith a computer, or a peripheral that is attached to a computer. In somedemonstrative embodiments, the term “wireless device” may optionallyinclude a wireless service.

Some demonstrative embodiments may be used in conjunction with suitablelimited-range or short-range wireless communication networks, forexample, a wireless area network, a “piconet”, a WPAN, a WVAN and thelike. Other embodiments may be used in conjunction with any othersuitable wireless communication network.

Some demonstrative embodiments may be used in conjunction with awireless communication network communicating over a frequency band of 60GHz. However, other embodiments may be implemented utilizing any othersuitable wireless communication frequency bands, for example, anExtremely High Frequency (EHF) band (the millimeter wave (mmwave)frequency band), e.g., a frequency band within the frequency band ofbetween 30 Ghz and 300 GHZ, a WLAN frequency band, a WPAN frequencyband, a frequency band according to the IEEE 802.11, IEEE 802.11TGadand/or WGA specifications, and the like.

The phrase “antenna assembly”, as used herein, may include any suitableconfiguration, structure and/or arrangement of one or more antennaelements, components, units and/or arrays. For example, an antennaassembly may include at least one of a phased array antenna, a singleelement antenna, a set of switched beam antennas, and the like. In someembodiments, the antenna assembly may implement transmit and receivefunctionalities using separate transmit and receive antenna elements. Insome embodiments, the antenna assembly may implement transmit andreceive functionalities using common and/or integrated transmit/receiveelements.

The phrase “quasi-omnidirectional antenna assembly”, as used herein, mayinclude an antenna assembly capable of at least receiving signals overat least a quasi-omnidirectional coverage pattern. Receiving signalsover a quasi-omnidirectional coverage pattern may include simultaneouslyreceiving signals in all directions of a given set of directions, e.g.,to cover a substantially continuous predefined coverage area, such thatin any certain direction within the set of directions the signals arereceived at a gain that is within a predefined margin, e.g., a margin of10 log₁₀(m), where m denotes a number of elements in a phased array,from a maximal gain provided by the antenna assembly, when directed toreceive and/or transmit in the certain direction. In some demonstrativeembodiments, the quasi-omnidirectional antenna assembly may include, orperform the functionality of, at least one quasi-omnidirectional receiveantenna or antenna element (RA) capable of receiving signals over thequasi-omnidirectional coverage pattern; and one or more transmit antennasectors (TS) covering one or more respective sectors of thequasi-omnidirectional coverage pattern. It will be appreciated that thephrase “quasi-omnidirectional antenna assembly”, as used herein, mayalso include any suitable omnidirectional or multidirectional antennaassembly.

Reference is now made to FIG. 1, which schematically illustrates a blockdiagram of a system 100 in accordance with some demonstrativeembodiments.

As shown in FIG. 1, in some demonstrative embodiments, system 100 mayinclude a wireless communication network including one or more wirelesscommunication devices, e.g., wireless communication devices 102 and/or130, capable of communicating content, data, information and/or signalsover one or more suitable wireless communication links, for example, aradio channel, an IR channel, a RF channel, a Wireless Fidelity (WiFi)channel, and the like. One or more elements of system 100 may optionallybe capable of communicating over any suitable wired communication links.

In some demonstrative embodiments, wireless communication devices 102and/or 130 may include, for example, a PC, a desktop computer, a mobilecomputer, a laptop computer, a notebook computer, a tablet computer, aserver computer, a handheld computer, a handheld device, a PDA device, ahandheld PDA device, an on-board device, an off-board device, a hybriddevice (e.g., combining cellular phone functionalities with PDA devicefunctionalities), a consumer device, a vehicular device, a non-vehiculardevice, a mobile or portable device, a non-mobile or non-portabledevice, a cellular telephone, a PCS device, a PDA device whichincorporates a wireless communication device, a mobile or portable GPSdevice, a DVB device, a relatively small computing device, a non-desktopcomputer, a “Carry Small Live Large” (CSLL) device, an Ultra MobileDevice (UMD), an Ultra Mobile PC (UMPC), a Mobile Internet Device (MID),an “Origami” device or computing device, a device that supportsDynamically Composable Computing (DCC), a context-aware device, a videodevice, an audio device, an A/V device, a STB, a BD player, a BDrecorder, a DVD player, a HD DVD player, a DVD recorder, a HD DVDrecorder, a PVR, a broadcast HD receiver, a video source, an audiosource, a video sink, an audio sink, a stereo tuner, a broadcast radioreceiver, a flat panel display, a PMP, a DVC, a digital audio player, aspeaker, an audio receiver, a gaming device, an audio amplifier, a datasource, a data sink, a DSC, a media player, a Smartphone, a television,a music player, or the like.

In some demonstrative embodiments, wireless communication devices 102and/or 130 may include wireless communication units 104 and/or 132,respectively, to perform wireless communication with wirelesscommunication devices 102 and/or 130, respectively, and/or with one ormore other wireless communication devices, e.g., as described below.Wireless communication devices 102 and/or 130 may also include, forexample, one or more of a processor 114, an input unit 106, an outputunit 108, a memory unit 110, and a storage unit 112. Wirelesscommunication devices 102 and/or 130 may optionally include othersuitable hardware components and/or software components. In somedemonstrative embodiments, some or all of the components of one or moreof wireless communication devices 102 and/or 130 may be enclosed in acommon housing or packaging, and may be interconnected or operablyassociated using one or more wired or wireless links. In otherembodiments, components of one or more of wireless communication devices102 and/or 130 may be distributed among multiple or separate devices.

Processor 114 includes, for example, a Central Processing Unit (CPU), aDigital Signal Processor (DSP), one or more processor cores, asingle-core processor, a dual-core processor, a multiple-core processor,a microprocessor, a host processor, a controller, a plurality ofprocessors or controllers, a chip, a microchip, one or more circuits,circuitry, a logic unit, an Integrated Circuit (IC), anApplication-Specific IC (ASIC), or any other suitable multi-purpose orspecific processor or controller. Processor 114 executes instructions,for example, of an Operating System (OS) of wireless communicationdevices 102 and/or 130 and/or of one or more suitable applications.

Input unit 106 includes, for example, a keyboard, a keypad, a mouse, atouch-pad, a track-ball, a stylus, a microphone, or other suitablepointing device or input device. Output unit 108 includes, for example,a monitor, a screen, a flat panel display, a Cathode Ray Tube (CRT)display unit, a Liquid Crystal Display (LCD) display unit, a plasmadisplay unit, one or more audio speakers or earphones, or other suitableoutput devices.

Memory unit 110 includes, for example, a Random Access Memory (RAM), aRead Only Memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM(SD-RAM), a flash memory, a volatile memory, a non-volatile memory, acache memory, a buffer, a short term memory unit, a long term memoryunit, or other suitable memory units. Storage unit 112 includes, forexample, a hard disk drive, a floppy disk drive, a Compact Disk (CD)drive, a CD-ROM drive, a DVD drive, or other suitable removable ornon-removable storage units. Memory unit 110 and/or storage unit 112,for example, may store data processed by wireless communication devices102 and/or 130.

In some demonstrative embodiments, wireless communication units 104and/or 132 include, for example, one or more wireless transmitters,receivers and/or transceivers able to send and/or receive wirelesscommunication signals, RF signals, frames, blocks, transmission streams,packets, messages, data items, and/or data. For example, wirelesscommunication units 104 and/or 132 may include or may be implemented aspart of a wireless Network Interface Card (NIC), and the like.

At least one of wireless communication unit 104 and 132 may include, ormay be associated with, a plurality of antenna assemblies. In oneembodiment, only one of wireless communication unit 104 and 132 mayinclude a plurality of antenna assemblies, while another one of wirelesscommunication units 104 and 132 may include a plurality of antennaassemblies. In another embodiment, each of wireless communication units104 and 132 may include a plurality of antenna assemblies. In oneexample, wireless communication unit 104 may include, or may beassociated with, a first number of antenna assemblies, e.g., two antennaassemblies 116 and 120; and/or wireless communication unit 132 mayinclude, or may be associated with a second number of antennaassemblies, e.g., three antenna assemblies 134, 136 and 138.

In some demonstrative embodiments, antenna assemblies 116 and 120 mayhave two respective, different, coverage areas. For example, antennaassemblies 116 and 120 may be positioned on first and second, e.g.,opposite, sides of device 102. Antenna assemblies 134, 136 and 138 mayhave three respective, different, coverage areas. For example, antennaassemblies 134, 136 and 138 may be positioned on three, different, sidesof device 130.

In some demonstrative embodiments, antenna assemblies 116, 120, 134, 136and/or 138 may include quasi-omnidirectional antenna assemblies. Forexample, each antenna assembly of assemblies 116, 120, 134, 136 and/or138 may include, or perform the functionality of, at least onequasi-omnidirectional receive antenna (RA) 126, e.g., such that RA 126may receive signals over a corresponding quasi-omnidirectional coveragepattern; and one or more transmit antenna sectors (TS) 124 covering oneor more respective sectors of the coverage area of thequasi-omnidirectional coverage pattern. In one example, one or moreantenna assemblies of antenna assemblies 116, 120, 134, 136 and/or 138may include, or may be implemented as part of, a suitable phased arrayantenna. In some embodiments, RA 126 and TS 124 of an antenna assemblymay be implemented by separate antenna elements of the antenna assembly.In other embodiments, RA 126 and TS 124 of the antenna assembly may beimplemented by a common antenna element, e.g., a suitablereceive/transmit element of the antenna assembly.

In some demonstrative embodiments, wireless communication units 104 and132 may implement a “training” session (or “beamforming training”),e.g., as part of establishing a first connection and/or associationbetween devices 102 and 130, to enable wireless communication unit 104to select an antenna assembly (“receive antenna assembly”), e.g., ofantenna assemblies 116 and 120, to be used for receiving transmissionsfrom wireless communication unit 132 and/or an antenna assembly(“transmit antenna assembly”), e.g., of antenna assemblies 116 and 120,to be used for transmitting transmissions to wireless communication unit132; and/or to enable wireless communication unit 132 to select areceive antenna assembly, e.g., of antenna assemblies 134, 136 and 138,to be used for receiving transmissions from wireless communication unit104 and/or a transmit antenna assembly, e.g., of antenna assemblies 134,136 and 138, to be used for transmitting transmissions to wirelesscommunication unit 104, e.g., as described in detail below.

In some demonstrative embodiments, a first wireless communication unit(“the initiator”) of wireless communication units 104 and 132, e.g.,wireless communication unit 104, may transmit a plurality of firsttraining transmissions, e.g., in the form of training packets, via oneor more antenna assemblies of the initiator, for example, while a secondwireless communication unit (“the responder”) of wireless communicationunits 104 and 132, e.g., wireless communication unit 132, may operateone or more antenna assemblies of the responder, e.g., in anomnidirectional receive mode, to receive the first trainingtransmissions; the responder may transmit a plurality of second trainingtransmissions, e.g., in the form of training packets, via one or more ofthe plurality of antenna assemblies of the responder, while theinitiator may operate the plurality of antenna assemblies of theinitiator to receive the second transmissions; and the initiator and/orresponder may select the receive and/or transmit antenna assembliesbased on the first and/or second training transmissions, e.g., asdescribed in detail below.

In some demonstrative embodiments, wireless communication unit 104 maytransmit a suitable training packet, e.g., including any suitablepredefined training sequence, via each TS 124 of each of antennaassemblies 116 and 120. The transmission of the training sequence mayinclude, for example, a training sequence suitable for reception at aSignal-to-Noise-Ratio (SNR), which is at least k decibel (dB) lower thana minimum SNR to be used for data transmission after the beamformingtraining is completed, e.g., wherein k=10 log₁₀(m), and m is the maximumnumber of antenna elements per assembly. For example, wirelesscommunication unit 104 may perform a sequence of sector scans (SS)including a first SS of antenna assembly 116 followed by a SS of antennaassembly 120. The SS of an antenna assembly may include any suitablealgorithm and/or method of sequentially transmitting a training packetvia each of the one or more transmit sectors 124 of the antennaassembly. For example, the SS of an antenna assembly including NStransmit sectors 124 may include sequentially transmitting NS trainingpackets via the NS transmit sectors 124, respectively.

In some demonstrative embodiments, wireless communication unit 104 mayperform the SS sequence, e.g., for a number of times equal to or greaterthan a number of the antenna assemblies of device 130. In one example,wireless communication unit 104 may perform the SS sequence for threetimes, for example, if wireless communication unit 104 is provided withinformation indicating that device 130 includes three antennaassemblies, e.g., as described below. In another example, wirelesscommunication unit 104 may repeatedly perform the SS sequence, e.g.,during a plurality of constant scan intervals, for example, if wirelesscommunication unit 104 is not provided with information indicating thenumber of antenna assemblies implemented by device 130, e.g., asdescribed below.

In some demonstrative embodiments, wireless communication unit 104 mayinclude, in each training packet transmitted via a TS 124 of an antennaassembly of antenna assemblies 116 and 120, an identification of theantenna assembly and the TS 124. For example, antenna assembly 116 maybe assigned a first identification value, e.g., zero; antenna assembly120 may be assigned a second identification value, e.g., one; and eachof TS 124 may be assigned with a different identification value, e.g.,between one and the number of TS 124.

In some demonstrative embodiments, wireless communication unit 104 mayinclude in each training packet a value indicating a remaining number oftraining packets to be transmitted successive to the training packet.

In some demonstrative embodiments, wireless communication unit 132 mayreceive at least some of the first training packets. Wirelesscommunication unit 132 may select, e.g., based on the received firsttraining packets, the responder receive antenna assembly, e.g., ofantenna assemblies 134, 136 and 138, to be used for receivingtransmissions from wireless communication unit 104. For example,wireless communication unit 132 may select from antenna assemblies 134,136 and 138 the antenna assembly providing the best reception of thefirst training packets, e.g., the antenna assembly providing the bestSignal-to-Noise-Ratio (SNR), and/or based on any other suitable criteriaand/or parameter.

In some demonstrative embodiments, wireless communication unit 132 maytransmit a suitable training packet, e.g., including any suitablepredefined training sequence, via each TS 124 of each of one or more ofantenna assemblies 134, 136 and 138. For example, wireless communicationunit 132 may perform a sequence of SS including one or more of a SS ofantenna assembly 134, a SS of antenna assembly 136, and a SS of antennaassembly 138.

In some demonstrative embodiments, the SS sequence may include a SS ofeach of antenna assemblies 134, 136 and 138. For example, wirelesscommunication unit 132 may perform a sequence of SS including a first SSof antenna assembly 134, followed by a second SS of antenna assembly136, and a third SS of antenna assembly 138. In other embodiments, theSS sequence may include a SS of less than all of antenna assemblies 134,136 and 138, for example, a SS of only one of antenna assemblies 134,136 and 138, e.g., as described below. In one example, the SS sequencemay include a SS of the selected responder receive antenna assembly, forexample, if antenna reciprocity is assumed, e.g., as described below.

In some demonstrative embodiments, wireless communication unit 132 mayperform the SS sequence, e.g., for a number of times equal to a numberof the antenna assemblies of device 102. For example, wirelesscommunication unit 132 may perform the SS sequence for two times, to bereceived by the two antenna assemblies 116 and 120, respectively. Inother demonstrative embodiments, wireless communication unit 132 mayperform the SS sequence for a number of times lesser than the number ofthe antenna assemblies of device 102. For example, wirelesscommunication unit 132 may perform a single SS sequence, e.g., asdescribed below.

In some demonstrative embodiments, wireless communication unit 132 mayinclude in each training packet transmitted via a TS 124 of an antennaassembly an identification of the antenna assembly and the TS 124.

In some demonstrative embodiments, wireless communication unit 132 mayidentify, e.g., based on the received first training packets, an antennaassembly of antenna assemblies 116 and 120 (“the identified initiatortransmit antenna assembly”), and/or one or more TS 124 of the identifiedantenna assembly (“the identified initiator TS”) providing the bestreception of the first training packets at device 130.

In some demonstrative embodiments, wireless communication unit 132 mayalso include in each of the second training packets a feedbackindication of the identified initiator transmit antenna assembly and/orthe identified initiator TS of device 102.

In some demonstrative embodiments, wireless communication unit 104 mayreceive at least some of the second training packets.

In some demonstrative embodiments, wireless communication unit 104 mayselect, e.g., based on the received second training packets, theinitiator transmit antenna assembly, e.g., of antenna assemblies 116 and120, to be used for transmitting transmissions to wireless communicationunit 132. For example, wireless communication unit 104 may select theinitiator transmit antenna assembly to include the identified initiatortransmit antenna assembly, as indicated by the second training packets.

In some demonstrative embodiments, wireless communication unit 104 mayselect, e.g., based on the received second training packets, one or moreTS 124 of the initiator transmit antenna assembly to be used fortransmitting transmissions to wireless communication unit 132. Forexample, wireless communication unit 104 may select the one or more TS124 to include the identified initiator TS, as indicated by the secondtraining packets.

In some demonstrative embodiments, wireless communication unit 104 mayselect, e.g., based on the received second training packets, theinitiator receive antenna assembly, e.g., of antenna assemblies 116 and120, to be used for receiving transmissions from wireless communicationunit 132. For example, wireless communication unit 104 may select fromantenna assemblies 116 and 120 the antenna assembly providing the bestreception of the second training packets, e.g., the antenna assemblyproviding the best SNR, and/or based on any other suitable criteriaand/or parameter.

In some demonstrative embodiments, wireless communication unit 104 mayidentify, e.g., based on the received second training packets, anantenna assembly of antenna assemblies 134, 136 and 138 (“the identifiedresponder transmit antenna assembly”), and/or one or more TS 124 of theidentified antenna assembly (“the identified responder TS”) providingthe best reception of the second training packets at device 102.

In some demonstrative embodiments, wireless communication unit 104 maytransmit to wireless communication unit 132 a feedback indication of theidentified responder transmit antenna assembly and/or the identifiedresponder TS of device 130. For example, wireless communication unit 104may transmit the feedback to wireless communication unit 132 in the formof, or as part of, any suitable feedback frame; and/or wirelesscommunication unit 132 may acknowledge the receipt of the feedback frameby transmitting a suitable acknowledgement (ACK) frame.

In some demonstrative embodiments, wireless communication unit 132 mayselect, e.g., based on the feedback from wireless communication unit104, the responder transmit antenna assembly, e.g., of antennaassemblies 134, 136 and 138, to be used for transmitting transmissionsto wireless communication unit 104. For example, wireless communicationunit 132 may select the responder transmit antenna assembly to includethe identified responder transmit antenna assembly, as indicated by thefeedback from wireless communication unit 104. In some demonstrativeembodiments, wireless communication unit 132 may select, e.g., based onthe feedback from wireless communication unit 104, one or more TS 124 ofthe responder transmit antenna assembly to be used for transmittingtransmissions to wireless communication unit 104. For example, wirelesscommunication unit 132 may select the one or more TS 124 to include theidentified responder TS, as indicated by the feedback from wirelesscommunication unit 104.

Reference is made to FIG. 2, which schematically illustrates a trainingsession 200 between an initiator and a responder, in accordance with onedemonstrative embodiment. In some embodiments, the training session ofFIG. 2 may be implemented by any suitable “initiator” and “responder”devices and/or units, e.g., wireless communication units 104 (FIG. 1)and/or 132 (FIG. 1).

According to the embodiments of FIG. 2, the initiator, e.g., device 102(FIG. 1), may include a first number, denoted NA_(I), of antennaassemblies, for example, NA_(I)=2 antenna assemblies, e.g., antennaassemblies 116 and 120 (FIG. 1); and the responder, e.g., device 130(FIG. 1), may include a second number, denoted NA_(R), of antennaassemblies, for example, NA_(R)=3 antenna assemblies, e.g., antennaassemblies 134, 136 and 138 (FIG. 1). The NA_(I) antenna assemblies mayinclude a total number, denoted NS_(I), of transmit sectors; and theNA_(R) antenna assemblies may include a total number, denoted NS_(R), oftransmit sectors.

According to the embodiments of FIG. 2, the initiator may be providedwith configuration information indicating the number of the NA_(R)antenna assemblies of the responder. The configuration information maybe provided to the initiator in any suitable manner, e.g., as part of aconfiguration and/or via information received from the responder and/orany other device.

In some demonstrative embodiments, the initiator may transmit a firstplurality of training transmissions via each of the NS_(I) transmitsectors, for example, by repeating, for NA_(R) times, the transmittingof NS_(I) training packets via the transmit sectors of the NA_(I)antenna assemblies, thereby allowing the responder to receive, via eachof the antenna assemblies of the responder, the training transmissionsfrom all the transmit sectors of the initiator. For example, theresponder may sequentially switch between the NA_(R) antenna assembliesof the responder, e.g., every switching period, which may be equal tothe aggregated time packet transmission time of NS_(I) training packets.

As shown in FIG. 2, the initiator may transmit a first sequence 202 ofSS, during a time period 214 in which the responder is to attempt toreceive the first sequence via a first antenna assembly, e.g., antennaassembly 134 (FIG. 1), of the responder. The sequence of SS 202 mayinclude performing a first SS 203 via a first antenna assembly, e.g.,antenna assembly 116 (FIG. 1), of the initiator followed by a second SS205 via a second antenna assembly, e.g., antenna assembly 120 (FIG. 1),of the initiator. The initiator may transmit a second sequence 206 ofSS, during a time period 216 in which the responder is to attempt toreceive the second sequence via a second antenna assembly, e.g., antennaassembly 136 (FIG. 1), of the responder. The sequence of SS 206 mayinclude performing a first SS 207 via a first antenna assembly, e.g.,antenna assembly 116 (FIG. 1), of the initiator followed by a second SS208 via a second antenna assembly, e.g., antenna assembly 120 (FIG. 1),of the initiator. The initiator may transmit a third sequence 210 of SS,during a time period 218 in which the responder is to attempt to receivethe third sequence via a third antenna assembly, e.g., antenna assembly138 (FIG. 1), of the responder. The sequence of SS 210 may includeperforming a first SS 211 via a first antenna assembly, e.g., antennaassembly 116 (FIG. 1), of the initiator followed by a second SS 212 viaa second antenna assembly, e.g., antenna assembly 120 (FIG. 1), of theinitiator.

In some demonstrative embodiments, the responder may receive at leastsome of the first training packets of SS 202, 206 and 210. The respondermay select, e.g., based on the received first training packets, theresponder receive antenna assembly to be used for receivingtransmissions from the initiator, e.g., s described above.

In some demonstrative embodiments, the responder may transmit a secondplurality of training transmissions via each of the NS_(R) transmitsectors, for example, by transmitting _(I) training packets via each ofthe NS_(R) transmit sectors of the NA_(R) antenna assemblies NA_(I)times, while the initiator may operate at a receive mode to attempt andreceive the second plurality of transmissions, for example, bysequentially switching between the NA₁ antenna assemblies of theinitiator, e.g., every switching period, which may be equal to theaggregated time packet transmission time of NS₂ training packets.

As shown in FIG. 2, the responder may transmit a first sequence 220 ofSS, during a time period 228 in which the initiator is to attempt toreceive the first sequence via a first antenna assembly, e.g., antennaassembly 116 (FIG. 1), of the initiator. The sequence of SS 220 mayinclude performing a first SS 221 via a first antenna assembly, e.g.,antenna assembly 134 (FIG. 1), of the responder followed by a second SS222 via a second antenna assembly, e.g., antenna assembly 136 (FIG. 1),of the responder, and by a third SS 223 via a third antenna assembly,e.g., antenna assembly 138 (FIG. 1), of the responder. The responder maytransmit a second sequence 224 of SS, during a time period 230 in whichthe initiator is to attempt to receive the second sequence via a secondantenna assembly, e.g., antenna assembly 120 (FIG. 1), of the initiator.The sequence of SS 224 may include performing a first SS 225 via a firstantenna assembly, e.g., antenna assembly 134 (FIG. 1), of the responderfollowed by a second SS 226 via a second antenna assembly, e.g., antennaassembly 136 (FIG. 1), of the responder, and by a third SS 227 via athird antenna assembly, e.g., antenna assembly 138 (FIG. 1), of theresponder.

Reference is made to FIG. 3, which schematically illustrates a trainingsession 300 between an initiator and a responder, in accordance withanother demonstrative embodiment. In some embodiments, the trainingsession of FIG. 3 may be implemented by any suitable “initiator” and“responder” devices and/or units, e.g., wireless communication units 104(FIG. 1) and/or 132 (FIG. 1).

According to the embodiments of FIG. 3, the initiator, e.g., device 102(FIG. 1), may include NA_(I) antenna assemblies and the responder, e.g.,device 130 (FIG. 1), may include NA_(R) antenna assemblies, e.g., asdescribed above with reference to FIG. 2.

According to the embodiments of FIG. 3, the initiator may perform NA_(R)sequences of SS, e.g., as described above with reference to FIG. 2.

According to the embodiments of FIG. 3, antenna reciprocity of theinitiator and the responder may be assumed. According to thisassumption, the selected responder receive antenna assembly may also beassumed as the selected responder transmit antenna assembly; and theidentified initiator transmitter antenna assembly, which is identifiedby the responder based on the first transmissions, may also be assumedto be the selected initiator receive antenna assembly and the selectedinitiator receive antenna assembly. Accordingly, the secondtransmissions from the responder to the initiator may be used forinforming the initiator of the selected antenna assemblies. For example,the responder may perform sector scans from only the selected responderreceive antenna assembly and/or may transmit the second training packetsonly to the identified initiator transmit antenna assembly.

As shown in FIG. 3, the responder may transmit a SS of the secondtraining packets from the selected responder transmit antenna assembly,during a time period in which the initiator is attempting to receive thesecond training packets via the identified initiator transmit antennaassembly. For example, the initiator, which may not have informationrelating to the identified initiator transmit antenna assembly, mayattempt to receive the second training packets via a first antennaassembly, e.g., antenna assembly 116 (FIG. 1), of the initiator during afirst time period 302; and the initiator may attempt to receive thesecond training packets via a second antenna assembly, e.g., antennaassembly 120 (FIG. 1), of the initiator during a second time period 304.The responder may perform a SS to transmit the second training packets303 via the selected responder receive antenna assembly during the timeperiod 302, e.g., if the identified initiator transmit antenna assemblyincludes the first antenna assembly, e.g., antenna assembly 116 (FIG.1), of the initiator; or during the time period 304, e.g., if theidentified initiator transmit antenna assembly includes the secondantenna assembly, e.g., antenna assembly 120 (FIG. 1), of the initiator.Time periods 302 and/or 304, during which the initiator may attempt toreceive the second training packets from the responder, may be shorter,for example, than time periods 228 and/or 230 (FIG. 2), respectively,since, for example, time periods 302 and/or 304 may be required toaccommodate the transmission time of a single SS, e.g., in opposed totime periods 228 and/or 230 (FIG. 2), which may be required toaccommodate the transmission time of three SS.

Referring back to FIG. 1, in some demonstrative embodiments, wirelesscommunication unit 104 may not have information indicating the numberand/or configuration of antenna assemblies implemented by device 130;and/or wireless communication unit 132 may not have informationindicating the number and/or configuration of antenna assembliesimplemented by device 104. According to these embodiments, wirelesscommunication units 104 and/or 132 may not have information defining atime for simultaneously starting to perform the training session; and/orwireless communication units 104 and/or 132 may not have information theduration of the SS sequences performed by wireless communication units132 and/or 104, respectively.

Reference is also made to FIG. 4, which schematically illustrates atraining session 400 between an initiator and a responder, in accordancewith another demonstrative embodiment. In some embodiments, the trainingsession of FIG. 4 may be implemented by any suitable “initiator” and“responder” devices and/or units, e.g., wireless communication units 104(FIG. 1) and/or 132 (FIG. 1).

In some demonstrative embodiments, wireless communication unit 104(FIG. 1) may repeatedly perform the SS sequence 403 of the transmissionof the first training packets during a plurality of constant timeperiods (“scan intervals”) 402, which may enable wireless communicationunit 132 (FIG. 1) to detect the first training packets via at least oneantenna assembly of wireless communication unit 132 (FIG. 1). The scaninterval 402 may include a time period which is less than or equal to amaximal scan interval which may be predefined and/or preset at wirelesscommunication units 104 and 132 (FIG. 1).

In some demonstrative embodiments, wireless communication unit 132(FIG. 1) may switch between antenna assemblies 134, 136 and 138 (FIG.1), e.g., at a rate of every scan interval 402, to attempt and receivethe first training packets from wireless communication unit 104 (FIG.1).

In some demonstrative embodiments, upon receiving at least one of thefirst training packets, wireless communication unit 132 may determine atime at which each of scan intervals 402 begins, e.g., based on thereceived first training packet. Accordingly, wireless communication unit132 (FIG. 1) may switch between the NA_(R) antenna assemblies 134, 136and 138 (FIG. 1) of wireless communication unit 132 (FIG. 1) to receivethe SS sequence of the first training packets via the NA_(R) antennaassemblies, e.g., during a time period 404 including NR₂ respective scanintervals 402, e.g., in analogy to the description above with referenceto FIG. 2. Wireless communication unit 132 (FIG. 1) may determine theselected responder receive antenna assembly, the identified initiatortransmit antenna assembly and/or the identified initiator TS, e.g.,based on the received first training packets, as described above.

In some demonstrative embodiments, a time period 405, within each scaninterval 402 may be allocated for wireless communication unit 132(FIG. 1) to perform the sequence of SS for transmitting the secondtraining packets; and for wireless communication unit 104 (FIG. 1) toattempt and receive the second training packets via each of antennaassemblies 116 and 120 (FIG. 1), e.g., as described above with referenceto FIG. 2. The duration of time period 405 may be reduced, for example,if antenna reciprocity is assumed, e.g., as described above withreference to FIG. 3. Wireless communication unit 104 (FIG. 1) may informwireless communication unit 132 (FIG. 1) of the length and/or timing ofthe scan interval 402, for example, by transmitting an indication ofwhen scan interval 402 begins and/or the length of time interval, e.g.,as part of each training packet.

Reference is also made to FIG. 5, which schematically illustrates atraining session 500 between an initiator and a responder, in accordancewith another demonstrative embodiment. In some embodiments, the trainingsession of FIG. 5 may be implemented by any suitable “initiator” and“responder” devices and/or units, e.g., wireless communication units 104(FIG. 1) and/or 132 (FIG. 1).

In some demonstrative embodiments, the initiator may perform a single SSsequence 502 to transmit the first training packets via each TS of eachof the antenna assemblies of the initiator, e.g., as described above.For example, SS sequence 502 may include performing a first SS 503 via afirst antenna assembly, e.g., antenna assembly 116 (FIG. 1), of theinitiator followed by a second SS 505 via a second antenna assembly,e.g., antenna assembly 120 (FIG. 1), of the initiator.

In some demonstrative embodiments, each of the first training packetstransmitted during SS sequence 502 may include a detection preamblehaving a duration (“the preamble length”), which is equal to or longerthan a time period required for the responder to attempt to detect thefirst training packets via each antenna assembly of the responder. Inone example, it may be assumed that the responder includes less thanfour antenna assemblies. According to this example, the preamble lengthmay be 8*Td, wherein Td denotes the duration required forreceiving/detecting a packet, for example, in order to allow theresponder up to a time period of 4*Td to detect the preamble by sweepingthrough the four antenna assemblies, and to allow the responder up to anadditional time period of 4*Td to detect the preamble via each of thefour assemblies, in order to determine which of the four assemblies isto be selected for reception. The responder may determine the selectedresponder receive antenna assembly, the identified initiator transmitantenna assembly and/or the identified initiator TS, e.g., based on thereceived first training packets, as described above.

In some demonstrative embodiments, assuming antenna reciprocity, theresponder may perform a SS 504 for transmitting the second trainingpackets via the selected responder receive antenna assembly, while theinitiator may sweep, during a time period 506, through the antennaassemblies of the initiator at a rate of the preamble length, to receivethe second training packets.

Reference is made to FIG. 6, which schematically illustrates a method ofcommunicating via multiple antenna assemblies, in accordance with somedemonstrative embodiments. In some embodiments, one or more of theoperations of the method of FIG. 6 may be performed by any suitablewireless communication system e.g., system 100 (FIG. 1); wirelesscommunication device, e.g., devices 102 and/or 130 (FIG. 1); and/orwireless communication unit, e.g., wireless communication units 104and/or 132 (FIG. 1).

As indicated at block 602, the method may include transmitting, via eachquasi-omnidirectional antenna assembly of one or morequasi-omnidirectional antenna assemblies of a first device, a pluralityof first transmissions. For example, wireless communication unit 104(FIG. 1) may transmit a plurality of first transmissions via each ofantenna assemblies 116 and 120 (FIG. 1), e.g., as described above.

As indicated at block 604, transmitting the plurality of firsttransmissions may include performing a plurality of SS sequences,wherein each SS sequence includes performing a plurality of SS of theantenna assemblies, respectively. For example, wireless communicationunit 104 (FIG. 1) may perform SS sequences 202, 206 and 210 (FIG. 2),e.g., a described above.

As indicated at block 606, transmitting the plurality of firsttransmissions may include transmitting a plurality of first trainingpackets via each transmit antenna sector of each quasi-omnidirectionalantenna assembly. For example, wireless communication unit 104 mayperform SS 202, 206 and 210 (FIG. 2), each including transmitting atraining packet via each TS of the corresponding antenna assembly, e.g.,as described above.

In some demonstrative embodiments, the plurality of first trainingpackets includes a number of packets equal to a number of a plurality ofquasi-omnidirectional antenna assemblies of the second device, forexample, if the number of quasi-omnidirectional antenna assemblies ofthe second device is known at the first device, e.g., as described abovewith reference to FIGS. 2 and/or 3.

In some demonstrative embodiments, the method may include repeating thetransmission of the plurality of first transmissions during a pluralityof constant scan intervals, for example, if the number ofquasi-omnidirectional antenna assemblies of the second device is notknown at the first device, e.g., as described above with reference toFIG. 4.

As indicated at block 608, the method may include receiving, in responseto the first transmissions, a plurality of second transmissions from asecond device via one or more of the quasi-omnidirectional antennaassemblies. For example, wireless communication unit 104 (FIG. 1) mayreceive, via antenna assemblies 116 and/or 120 (FIG. 1), a plurality ofsecond training packets transmitted by antenna assemblies 134, 136and/or 138 (FIG. 1) of device 130 (FIG. 1), e.g., as described above.

As indicated at block 610, receiving the second transmissions mayinclude sweeping between antenna assemblies. For example, wirelesscommunication unit 104 (FIG. 1) may sweep between antenna assemblies 116and 120 (FIG. 1) during time periods 228 and 230 (FIG. 2), e.g., asdescribed above.

As indicated at block 612, the method may include selecting at the firstdevice, based on the second transmissions, at least one selectedtransmit antenna assembly for transmitting to the second device and aselected receive antenna assembly for receiving transmissions from thesecond device. For example, wireless communication unit may determinethe selected initiator transmit antenna assembly, the selected initiatorTS, and/or the selected initiator receive antenna assembly based on thetransmissions received from wireless communication unit 132 (FIG. 1),e.g., as described above.

In some demonstrative embodiments, at least one transmission of thesecond transmissions may include an indication of an antenna assembly ofthe antenna assemblies of the first device and an indication of at leastone transmit antenna sector of the indicated antenna assembly, andselecting the initiator transmit antenna may include selecting theindicated transmit antenna sector, e.g., as described above.

As indicated at block 614, the method may include transmitting to thesecond device an indication of at least one antenna assembly and/or TSof the plurality of antenna assemblies of the second device to be usedby the second device for transmitting to the first device. For example,wireless communication unit 104 (FIG. 1) may identify antenna assemblyand/or a TS 124 (FIG. 1) of device 130 (FIG. 1) based on the secondtraining packets received by wireless communication unit 104 (FIG. 1),and transmit to wireless communication unit 132 (FIG. 1) an indicationof the identified antenna assembly and/or TS, e.g., as described above.

Reference is made to FIG. 7, which schematically illustrates an articleof manufacture 700, in accordance with some demonstrative embodiments.Article 700 may include a machine-readable storage medium 702 to storelogic 704, which may be used, for example, to perform at least part ofthe functionality of wireless communication unit 104 (FIG. 1), wirelesscommunication device 102 (FIG. 1), wireless communication unit 132 (FIG.1), wireless communication device 130 (FIG. 1); and/or to perform one ormore operations of the method of FIG. 6.

In some demonstrative embodiments, article 700 and/or machine-readablestorage medium 702 may include one or more types of computer-readablestorage media capable of storing data, including volatile memory,non-volatile memory, removable or non-removable memory, erasable ornon-erasable memory, writeable or re-writeable memory, and the like. Forexample, machine-readable storage medium 702 may include, RAM, DRAM,Double-Data-Rate DRAM (DDR-DRAM), SDRAM, static RAM (SRAM), ROM,programmable ROM (PROM), erasable programmable ROM (EPROM), electricallyerasable programmable ROM (EEPROM), Compact Disk ROM (CD-ROM), CompactDisk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), flash memory(e.g., NOR or NAND flash memory), content addressable memory (CAM),polymer memory, phase-change memory, ferroelectric memory,silicon-oxide-nitride-oxide-silicon (SONOS) memory, a disk, a floppydisk, a hard drive, an optical disk, a magnetic disk, a card, a magneticcard, an optical card, a tape, a cassette, and the like. Thecomputer-readable storage media may include any suitable media involvedwith downloading or transferring a computer program from a remotecomputer to a requesting computer carried by data signals embodied in acarrier wave or other propagation medium through a communication link,e.g., a modem, radio or network connection.

In some demonstrative embodiments, logic 704 may include instructions,data, and/or code, which, if executed by a machine, may cause themachine to perform a method, process and/or operations as describedherein. The machine may include, for example, any suitable processingplatform, computing platform, computing device, processing device,computing system, processing system, computer, processor, or the like,and may be implemented using any suitable combination of hardware,software, firmware, and the like.

In some demonstrative embodiments, logic 704 may include, or may beimplemented as, software, a software module, an application, a program,a subroutine, instructions, an instruction set, computing code, words,values, symbols, and the like. The instructions may include any suitabletype of code, such as source code, compiled code, interpreted code,executable code, static code, dynamic code, and the like. Theinstructions may be implemented according to a predefined computerlanguage, manner or syntax, for instructing a processor to perform acertain function. The instructions may be implemented using any suitablehigh-level, low-level, object-oriented, visual, compiled and/orinterpreted programming language, such as C, C++, Java, BASIC, Matlab,Pascal, Visual BASIC, assembly language, machine code, and the like.

Functions, operations, components and/or features described herein withreference to one or more embodiments, may be combined with, or may beutilized in combination with, one or more other functions, operations,components and/or features described herein with reference to one ormore other embodiments, or vice versa.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. It is, therefore, tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of theinvention.

The invention claimed is:
 1. An apparatus comprising: a memory; and aprocessor configured to cause a responder station (STA) of a Beamforming(BF) training to: operate at least one antenna of the responder STA toreceive at least one initiator BF training frame from an initiator STA,the initiator BF training frame comprising an antenna identifier toidentify an antenna of the initiator STA to transmit the initiator BFtraining frame, and a sector identifier to identify a sector of theinitiator STA to transmit the initiator BF training frame; determine aresponder-identified antenna of the initiator STA and aresponder-identified sector of the initiator STA based on the at leastone initiator BF training frame; and transmit at least one responder BFtraining frame to the initiator STA, the responder BF training framecomprising an indication of the responder-identified antenna of theinitiator STA and the responder-identified sector of the initiator STA.2. The apparatus of claim 1 configured to cause the responder STA totransmit a plurality of responder BF training frames during one or morerepetitions of a Transmit (Tx) Sector Sweep (TxSS) over one or moreantennas of the responder STA, a count of the one or more repetitions ofthe TxSS is based on a count of antennas of the initiator STA.
 3. Theapparatus of claim 1 configured to cause the responder STA to, whenantenna reciprocity is to be implemented, determine a selected antennaof a plurality of antennas of the responder STA based on the at leastone initiator BF training frame, and transmit the at least one responderBF training frame via the selected antenna of the responder STA.
 4. Theapparatus of claim 3 configured to cause the responder STA to determinethe selected antenna of the responder STA based on a best receivedinitiator BF training frame of the at least one initiator BF trainingframe.
 5. The apparatus of claim 1 configured to cause the responder STAto, when antenna reciprocity is not to be implemented, sequentiallyswitch between a plurality of antennas of the responder STA to transmitthe at least one responder BF training frame.
 6. The apparatus of claim1, wherein the responder BF training frame comprises a responder antennaidentifier to identify an antenna of the responder STA to transmit theresponder BF training frame, and a responder sector identifier toidentify a sector of the responder STA to transmit the responder BFtraining frame.
 7. The apparatus of claim 1 configured to cause theresponder STA to receive a feedback frame from the initiator STA, thefeedback frame comprising an initiator-identified antenna of theresponder STA and an initiator-identified sector of the responder STA.8. The apparatus of claim 7 configured to cause the responder STA todetermine a transmit antenna to transmit to the initiator STA based onthe initiator-identified antenna, and to determine a transmit sector totransmit to the initiator STA based on the initiator-identified sector.9. The apparatus of claim 7 configured to cause the responder STA totransmit an acknowledgement to the initiator STA following the feedbackframe.
 10. The apparatus of claim 1 configured to cause the responderSTA to determine the responder-identified antenna and theresponder-identified sector according to a best received initiator BFtraining frame of the at least one initiator BF training frame.
 11. Theapparatus of claim 1, wherein the initiator BF training frame comprisesan indication of a remaining number of initiator BF training frames tobe transmitted.
 12. The apparatus of claim 1, wherein the at least oneresponder BF training frame comprises a plurality of responder BFtraining frames, each of the plurality of responder BF training framescomprising a same indication of the responder-identified sector and theresponder-identified antenna.
 13. The apparatus of claim 1 configured tocause the responder STA to operate the at least one antenna of theresponder STA at a quasi-omnidirectional antenna pattern to receive theat least one initiator BF training frame.
 14. The apparatus of claim 1configured to cause the responder STA to switch between a plurality ofantennas of the responder STA to receive the at least one initiator BFtraining frame.
 15. The apparatus of claim 1 comprising a radio.
 16. Theapparatus of claim 1 comprising the plurality of antennas of theinitiator STA.
 17. A product comprising one or more tangiblecomputer-readable non-transitory storage media comprisingcomputer-executable instructions operable to, when executed by at leastone processor, enable the at least one processor to cause a responderstation (STA) of a Beamforming (BF) training to: operate at least oneantenna of the responder STA to receive at least one initiator BFtraining frame from an initiator STA, the initiator BF training framecomprising an antenna identifier to identify an antenna of the initiatorSTA to transmit the initiator BF training frame, and a sector identifierto identify a sector of the initiator STA to transmit the initiator BFtraining frame; determine a responder-identified antenna of theinitiator STA and a responder-identified sector of the initiator STAbased on the at least one initiator BF training frame; and transmit atleast one responder BF training frame to the initiator STA, theresponder BF training frame comprising an indication of theresponder-identified antenna of the initiator STA and theresponder-identified sector of the initiator STA.
 18. The product ofclaim 17, wherein the instructions, when executed, cause the responderSTA to transmit a plurality of responder BF training frames during oneor more repetitions of a Transmit (Tx) Sector Sweep (TxSS) over one ormore antennas of the responder STA, a count of the one or morerepetitions of the TxSS is based on a count of antennas of the initiatorSTA.
 19. The product of claim 17, wherein the instructions, whenexecuted, cause the responder STA to, when antenna reciprocity is to beimplemented, determine a selected antenna of a plurality of antennas ofthe responder STA based on the at least one initiator BF training frame,and transmit the at least one responder BF training frame via theselected antenna of the responder STA.
 20. The product of claim 17,wherein the instructions, when executed, cause the responder STA to,when antenna reciprocity is not to be implemented, sequentially switchbetween a plurality of antennas of the responder STA to transmit the atleast one responder BF training frame.
 21. The product of claim 17,wherein the responder BF training frame comprises a responder antennaidentifier to identify an antenna of the responder STA to transmit theresponder BF training frame, and a responder sector identifier toidentify a sector of the responder STA to transmit the responder BFtraining frame.
 22. The product of claim 17, wherein the instructions,when executed, cause the responder STA to receive a feedback frame fromthe initiator STA, the feedback frame comprising an initiator-identifiedantenna of the responder STA and an initiator-identified sector of theresponder STA.
 23. The product of claim 22, wherein the instructions,when executed, cause the responder STA to determine a transmit antennato transmit to the initiator STA based on the initiator-identifiedantenna, and to determine a transmit sector to transmit to the initiatorSTA based on the initiator-identified sector.
 24. An apparatuscomprising: means for operating at least one antenna of a responderstation (STA) of a Beamforming (BF) training to receive at least oneinitiator BF training frame from an initiator STA, the initiator BFtraining frame comprising an antenna identifier to identify an antennaof the initiator STA to transmit the initiator BF training frame, and asector identifier to identify a sector of the initiator STA to transmitthe initiator BF training frame; means for determining aresponder-identified antenna of the initiator STA and aresponder-identified sector of the initiator STA based on the at leastone initiator BF training frame; and means for causing the responder STAto transmit at least one responder BF training frame to the initiatorSTA, the responder BF training frame comprising an indication of theresponder-identified antenna of the initiator STA and theresponder-identified sector of the initiator STA.
 25. The apparatus ofclaim 24 comprising means for causing the responder STA to transmit aplurality of responder BF training frames during one or more repetitionsof a Transmit (Tx) Sector Sweep (TxSS) over one or more antennas of theresponder STA, a count of the one or more repetitions of the TxSS isbased on a count of antennas of the initiator STA.